With Single Sign On (SSO), a user can log in using a single identifier and password to gain access to multiple systems without having to use multiple user names and passwords for the multiple systems. Principal propagation is a process by which a sending system forwards user context information unchanged to a receiving system. SAML (Security Assertion Markup Language) is an open standard for exchanging authentication and authorization data between parties. OAuth2 (Open Authentication Version 2) is an open standard for access delegation.